The present invention relates to a system for applying adhesives to end jointed or laminated beams and more particularly to an adhesive application system which deposits metered amounts of adhesive in well defined predetermined areas.
In the past, adhesive application systems have used disc rollers for depositing adhesives on surfaces to be bonded in beam end joining processes. No control was exercised over the amount of adhesive applied so that an excess amount of adhesive was delivered to the bonding surfaces by the application head, resulting in an accumulation of adhesive on adjacent beam surfaces where bonding was not intended. The delivery of excess adhesive to surfaces to be bonded both increases adhesive consumption and causes jointed assemblies in storage to bond to adjacent assemblies, requiring extra labor to thereafter separate them. In prior art methods an attempt was made to retrieve the excess adhesive for recirculation in the adhesive application system. This allowed contaminants to enter the adhesive stream and in some instances physical damage was imparted to the adhesive through shear forces imposed during pumping, thus materially reducing the adhesive characteristics.
A new system and application head is needed which precisely meters adhesive to the surface to be bonded, precluding the necessity for an adhesive recovery and recirculation system.